The Sources of Labour Law has been published with Wolters Kluwer: https://lrus.wolterskluwer.com/store/product/the-sources-of-labour-law/.

The book deals with national sources of labour law and their changing hierarchy.

Horizontal chapters:
Tamás Gyulavári & Emanuele Menegatti: Recent Trends
Alan C. Neal: Historical Roots
Edoardo Ales: Regulatory Function of Collective Agreements
Joellen Riley Munton: Judge-Made Law in Common Law
Martin Risak: Role of Judges in Civil Law
Emanuele Menegatti: Impact of EU Economic Governance

National Reports
Andrew Stewart & Mark Bray (Australia); Jedidiah Kroncke (Brazil); Dong Yan (China); Christian Højer Schjøler (Denmark); Isabelle Daugareilh (France); Manfred Weiss (Germany); Tamás Gyulavári (Hungary); Iacopo Senatori (Italy); Łukasz Pisarczyk (Poland); Olga Rymkevich (Russia); José Maria Miranda Boto (Spain); Jenny Julén Votinius (Sweden); Rochelle Le Roux (South Africa); Michael Doherty & David Mangan (UK); Paul Secunda (USA)